[Back]


Publications in Scientific Journals:

F. Failamani, A. Grytsiv, R. Podloucky, H. Michor, E. Bauer, P. Broz, G. Giester, P. Rogl:
"The System Ce-Zn-Si for <33.3% at. Ce: Phase Relations, Crystal Structures and Physical Properties";
RSC Advances, 5 (2015), 36480 - 36497.



English abstract:
Phase equilibria of the system Ce-Zn-Si have been determined for the isothermal section at 600 C for <33.3 at.% Ce by XRPD and EPMA. This partial section is characterized by the formation of five ternary compounds with homogeneity regions at constant Ce-content and partial substitution of Zn/Si: τ1-Ce7Zn21(Zn1−xSix)2 (unique type; 0.45 ≤ x ≤ 0.99), τ2-Ce(Si1−xZnx)2 (AlB2-type; 0.36 ≤ x ≤ 0.73), τ5-CeZn(Zn1−xSix)2 (CeNiSi2-type; 0.68 ≤ x ≤ 0.76), τ6-CeZn2(Si1−xZnx)2 (ThCr2Si2-type; 0.25 ≤ x ≤ 0.30) and τ7-Ce37Zn48Si15 (structure unknown). Whereas τ1, τ2 and τ5 are stable at 600 and 800 C, the phases τ6, τ7 are unstable at 800 C. Atom site distribution in the crystal structures of τ5, τ6 and {La,Ce}7Zn21(Zn1−xGex)2 have been elucidated from X-ray intensity refinements on single crystals. The small amounts of the stabilizing tetrel element in {La,Ce}7Zn21[Zn1−xSi(Ge)x]2 suggest a hypothetical binary phase "{La,Ce}7Zn23". The stabilizing effect of Ge in Ce7Zn23−xGex has been elucidated from density functional theory (DFT) calculations discussing the electronic structure in terms of the density of states (DOS) and defining enthalpies of formation for Ce7Zn23−xGex (x = 0, 0.5, 2) as well as for several neighbouring binary Ce-Zn phases. A Schultz-Scheil diagram for the solidification behaviour in the (Zn,Si)-rich part of the diagram was constructed from DTA measurements in closed silica crucibles along with partial isothermal sections determined in the temperature range from 400 to 900 C. The phases τ5 and τ6 both form in degenerate ternary peritectic reactions: L + CeSi2,β-Ce2Zn17 ⇔ τ5 at 865 5 C and L + τ5,CeZn11 ⇔ τ6 at 695 5 C, respectively. Magnetic susceptibility, specific heat and resistivity measurements of τ5-CeZn(Zn1−xSix)2 revealed Kondo lattice behavior with ferromagnetic ordering below TC = 4.4 K, whereas susceptibility and specific heat studies of τ6-CeZn2(Zn0.28Si0.72)2 revealed Curie-Weiss paramagnetic behaviour down to 3 K. The effective paramagnetic moments of Ce obtained from Curie-Weiss fits of τ5 (2.50μB) and τ6 (2.34μB) reveal a ground state close to trivalent Ce.


"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1039/C5RA02789F


Created from the Publication Database of the Vienna University of Technology.